Safety cap for medicament vial having puncturable seal

Abstract

The safety cap of the present invention is for use with a medicament vial having a puncturable seal. The cap includes a cylindrical extension provided with a shape-retentive but slightly expandable cylindrical body slidable therein having a diametrically reduced sharpened tubular needle extension on its inner end for piercing the seal. The body includes first and second portions of slightly different diameters, with the portion of smaller diameter outermost, and an inwardly tapering center portion, thus defining two shoulders for cooperating with an inwardly projecting lip on the outer end of the cylindrical extension to resiliently resist inward movement of the body and to prevent outward withdrawal of the body after it has been pressed inwardly to puncture the seal. The body has a central bore formed therethrough defining an inwardly tapering passage and a larger diameter counterbore in which the pointed end of a hypodermic needle and the tapered tip extension of a conventional syringe barrel may be wedgingly and sealingly seated.

What is claimed as new is as follows: 
     
       1. For use in connection with a container having a puncturable seal, a closure cap for support from said container in position with a mounting portion of said cap disposed outwardly of said seal, a tubular needle structure having one pointed end supported from said mounting portion for movement toward and away from the outer side of said seal between a first position with said one pointed end retracted away from said seal and a second position with said one pointed end projected through the seal, said mounting portion of said cap and said needle structure including coacting means progressively and increasingly yieldingly resisting movement of said needle structure from said first position to a third position intermediate said first and second positions with said pointed end at least initially engaged with said seal and then releasing said needle structure for free movement from said third position to said second position. 
     
     
       2. The combination of claim 1 wherein said coacting means also includes means for positively preventing retractive movement of said needle structure from said second position toward said first position past said third position. 
     
     
       3. The combination of claim 2 wherein said mounting portion comprises a tubular support member in which said tubular needle structure is slidingly received, said coacting means including inwardly projecting lip means on the end of said tubular support member opposite to the pointed end of said needle structure and a shoulder on said needle structure opposing and engageable with said lip means, said shoulder on said needle structure being defined on the major diameter end of a frusto-conical outer surface portion of said needle structure tapering toward said one pointed end, said tubular support member being constructed of shape retentive but slightly expandable material whereby said lip means may be expanded over the major diameter end of said frusto-conical outer surface portion. 
     
     
       4. The combination of claim 3 wherein the outer end of said interior bore portion includes a slightly inwardly tapering larger diameter bore adapted to wedgingly and sealingly seatingly receive the slightly tapering tubular tip extension of a conventional syringe barrel therein. 
     
     
       5. For use in connection with a container having a puncturable seal, a closure cap for support from said container in position with a mounting portion of said cap disposed outwardly of said seal, a tubular needle structure having one pointed end supported from said mounting portion for movement toward and away from the outer side of said seal between a first position with said one pointed end retracted away from said seal and a second position with said one pointed end projected through the seal, said mounting portion comprising a tubular support member in which said tubular needle structure is slidingly received, said mounting portion of said cap and said needle structure including coacting means positively preventing retractive movement of said needle structure from said second position toward said first position past a third position intermediate said first and second positions, said coacting means including inwardly projecting lip means on the end of said tubular support member opposite to the pointed end of said needle structure and a shoulder on said needle structure opposing and engageable with said lip means, said shoulder on said needle structure being defined on the major diameter end of a frusto-conical outer surface portion of said needle structure tapering toward said one pointed end, said tubular support member being constructed of shape retentive but slightly expandable material whereby said lip means may be expanded over the major diameter end of said frusto-conical outer surface portion. 
     
     
       6. The combination of claim 5 wherein said tubular needle includes an interior thin walled bore portion tapering toward said one end of said needle structure and of a diameter adapted to wedgingly and sealingly seatingly receive the pointed end of a hypodermic needle therein with the needle releasably retentively retained in said tapering bore portion against withdrawal therefrom by a force below a predetermined value.